Decreased immune response to foot-and-mouth disease vaccination following synbiotic supplementation in Hanwoo (Bos taurus coreanae) cows

Foot-and-mouth disease (FMD) vaccination is known to increase ruminoreticular temperature, acute-phase immune proteins, and white blood cell counts. Recent studies indicate that synbiotic supplementation can help reduce stress by alleviating stress-induced intestinal inflammation. However, there are no studies on the stress of FMD vaccination according to synbiotic supplementation. Therefore, this study aimed to investigate the stress-relieving effects of synbiotic treatment by measuring ruminoreticular temperature, body activity, acute-phase immune protein concentrations, and complete blood count analysis following FMD vaccination. The study included three groups; the positive control group received only synbiotic supplementation for two weeks, the 2W_SB_FMD group received synbiotic supplementation for two weeks prior to FMD vaccination, and the 1W_SB_FMD group received synbiotic supplementation for one week prior to vaccination. Ruminoreticular temperature and body activity were measured before and after FMD vaccination. Blood samples were collected on days 0, 3, 6, and 10 relative to FMD vaccination, and concentrations of haptoglobin (HPT), serum amyloid A (SAA), and white blood cells (WBC) were analyzed. Compared to previous studies, the ruminoreticular temperature was significantly lower in the synbiotic-treated group compared to the FMD-only group 24 hours post-vaccination (p < 0.0001). Significant differences in body activity were also observed between the FMD-only group and the synbiotic-treated group (p < 0.0001), with the synbiotic-treated group exhibiting stable activity before and after vaccination. Levels of HPT and SAA, which indicate acute immune responses, increased until day 3 post-vaccination but then sharply declined between days 6 and 10. The lymphocyte ratio gradually decreased more in the 2W_SB_FMD group than in the 1W_SB_FMD group. Overall, synbiotic supplementation, which helps relieve stress by reducing intestinal inflammation, significantly influenced ruminoreticular temperature and HPT, SAA, and WBC concentrations depending on the duration of the synbiotic treatment. These findings suggest that synbiotic treatment following FMD vaccination may serve as an effective stress reliever.